A known image scanner or printer includes a sheet feeding device configured to feed sheets. For example, an image scanner includes a sheet feeding path extending through an image reading unit. The sheet feeding device feeds sheets along the sheet feeding path.
The sheet feeding device includes a guide member extending along the sheet feeding path and a roller member including a shaft and a roller mounted thereon. A side plate is provided on each side of the guide member. The guide member is supported by the side plates. Each side plate has a circular hole in which a bearing is fitted. The roller member is disposed between the side plates while each end of the shaft is rotatably inserted into the bearing.
As the roller member rotates, a feeding force is applied from the roller to a sheet making contact with a peripheral surface of the roller, so that a sheet is fed along the sheet feeding path. At this time, the guide member guides the sheet being fed.
To make the peripheral surface of the roller contact the sheet, a portion of the peripheral surface of the roller needs to protrude from the guide member toward the sheet feeding path. For example, an opening corresponding to the size of the roller is formed on the guide member. A portion of the peripheral surface of the roller may protrude from the guide member toward the sheet feeding path by disposing the roller in the opening from a side opposite to the sheet feeding path.